Reference for Question 1

Sales Database:

Customer(custId, lastName, firstName, address, phone, creditLimit)

Order(orderNumber, date, total, custId)

LineItem(orderNumber, itemNumber, qtyOrdered)

Item(itemNumber, itemName, price)

For the Sales Database in the reference, write the relational algebra expression for the query

Find the lastName of the customer for orderNumber 12345.

Reference for Question 2

Sales Database:

Customer(custId, lastName, firstName, address, phone, creditLimit)

Order(orderNumber, date, total, custId)

LineItem(orderNumber, itemNumber, qtyOrdered)

Item(itemNumber, itemName, price)

For the Sales Database in the reference, write the relational algebra expression for the query "Find the names and quantities of all items on order 12345."